451
FXUS62 KCAE 230042
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
842 PM EDT TUE SEP 22 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGE 1 TO REFLECT LATEST MESOANALYSIS AND
GUIDANCE. AVIATION DISCUSSION UPDATED FOR 00Z TAFS.
KEY MESSAGES
- 1. WARM AND HUMID WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING.
- 2. COOLER CONDITIONS EXPECTED WEDNESDAY ONWARD, WITH PERIODS
OF SHOWERS MAINLY WEDNESDAY AND THURSDAY.
DISCUSSION
KEY MESSAGE 1: WARM AND HUMID WITH SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING.
MIDDAY CONVECTION HAS STARTED TO DIMINISH ACROSS THE CENTRAL
MIDLANDS THIS EVENING WITH SOME SHOWERS STILL HANGING AROUND
NORTH OF I-20, CLOSER TO THE NC BORDER. LATEST MESOANALYSIS
SHOWS CAPE VALUES HAVE DIMINISHED ACROSS MUCH OF THE AREA WITH
HIGHER VALUES TO OUR WEST CLOSER TO THE FRONT. PWATS STILL
REMAIN IN THE 1.8-2" RANGE WITH EFFICIENT LOW-TOPPED CONVECTION
AND RAIN RATES IN THE 2-3" PER HOUR RANGE. A FEW STORMS HAVE
ALSO STARTED TO DEVELOP IN THE UPSTATE WHERE INSTABILITY REMAINS
ELEVATED. LATEST CAMS SHOW CONVECTION SHOULD DIMINISH HERE OVER
THE NEXT FEW HOURS AS WE LOSE DAYTIME HEATING. HOWEVER, ANY
STORMS/SHOWERS THIS EVENING COULD BRING GUSTY WINDS AND HEAVY
RAINFALL. A LOCALIZED FLASH FLOODING THREAT REMAINS THE MAIN
THREAT.
KEY MESSAGE 2: COOLER CONDITIONS EXPECTED WEDNESDAY ONWARD, WITH
PERIODS OF SHOWERS MAINLY WEDNESDAY AND THURSDAY.
MODELS ARE GENERALLY CONVERGING ON HIGH PRESSURE OVER THE
NORTHEAST PUSHING THE WEDGE FRONT THROUGH OUR FORECAST AREA
LATE TONIGHT INTO WEDNESDAY. THE ONGOING SHOWERS AND CLOUD
COVER WEDNESDAY MORNING WILL LIKELY LIMIT DAYTIME HEATING,
ESPECIALLY WITH COLD ADVECTION OCCURRING AT THE SURFACE. THERE
REMAINS SOME UNCERTAINTY REGARDING HOW FAR SOUTH THE WEDGE FRONT
WILL GO, AND IT IS EXPECTED TO HAVE A TIGHT TEMPERATURE
GRADIENT SETTING UP SOMEWHERE ACROSS THE SOUTHERN MIDLANDS
WEDNESDAY AFTERNOON. ALL SAID, THE TEMPERATURE DROP OF 10 TO 15+
DEGREES BETWEEN TUESDAY AND WEDNESDAY WILL BE VERY NOTICEABLE
NORTH OF THE FRONT. THERE WILL ALSO BE SOME BREEZY NORTHEAST
WINDS ACCOMPANYING THIS AIRMASS CHANGE. BLENDED GUIDANCE
STRUGGLES IN THESE SCENARIOS, SO WE HAVE BEEN USING THE NAM/GFS
MODELS TO BETTER CAPTURE THE EXPECTED TEMPERATURES LATE THIS
WEEK.
ADDITIONAL CLOUD COVER AND PRECIP SUGGESTS THURSDAY COULD BE OUR
COOLEST DAY OF THE WEEK FOR HIGH TEMPERATURES, WITH MOST EXPECTED TO
REMAIN IN THE LOW TO UPPER 70S. AN UPPER TROUGH WILL WORK TO SCOUR
OUT THE WEDGE THROUGH SOME PORTION OF THE DAY, WITH DRIER NORTHWEST
FLOW EVENTUALLY MOVING IN. HIGHS WILL REBOUND A BIT CLOSER TO NORMAL
AS PRECIP AND CLOUD FREE CONDITIONS RETURN FRIDAY AND INTO THIS
WEEKEND. HIGHS WILL GENERALLY REACH THE UPPER 70S TO LOW 80S, WITH
OVERNIGHT LOWS IN THE UPPER 50S TO LOW 60S. OVERALL, THIS SHOULD
PROVIDE OUR FIRST REAL TASTE OF FALL WITH A REFRESHING CHANGE IN
TEMPERATURES ARRIVING JUST AS ASTRONOMICAL AUTUMN OFFICIALLY BEGINS
LATER TODAY!
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
WIDELY SCATTERED SHOWERS AND STORMS POSSIBLE OVERNIGHT AS A COLD
FRONT PUSHES IN THE FROM THE NORTH ALONG WITH WIDESPREAD
RESTRICTIONS.
ALTHOUGH CONVECTIVE ACTIVITY WILL BE LOWER OVERNIGHT WE EXPECT
AT LEAST ISOLATED TO WIDELY SCATTERED STORMS TO CONTINUE INTO
THE LATE EVENING WITH CONTINUED SHOWERS OR LIGHT RAIN INTO THE
MORNING AS THE COLD FRONT PUSHES SOUTH INTO THE FORECAST AREA.
THIS FRONT WILL SET UP WEDGE CONDITIONS OVER THE REGION WITH
WIDESPREAD CEILING RESTRICTIONS AND A SHIFT TO NORTHERLY WINDS
BY 03Z-09Z. SOME UNCERTAINTY REMAINS REGARDING HOW FAR SOUTH THE
WEDGE WILL SETTLE IN BY WEDNESDAY MORNING, BUT IFR CEILINGS ARE
LIKELY AND WILL CONTINUE THROUGH THE MORNING AND POSSIBLY THE
REMAINDER OF THE DAY. THERE IS SOME POSSIBILITY OF SOME
IMPROVEMENT AT AGS, DNL AND OGB LATE MORNING BUT IT WOULD BE
SHORT LIVED AS THE FRONT CONTINUES SOUTH AND CEILINGS LOWER.
EXTENDED AVIATION OUTLOOK...WIDESPREAD RESTRICTIONS CONTINUE
THURSDAY AS WEDGE CONDITIONS REMAIN OVER THE REGION WITH SHOWERS
LIKELY. DRIER CONDITIONS EXPECTED BEGINNING FRIDAY BUT LOW
CEILINGS MAY PERSIST LONGER THAN MODEL GUIDANCE SUGGESTS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...7/ND
AVIATION...CJR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page